Envelhecimento e rejuvenescimento de software: 20 anos (19952014) - panorama e desafios

Although software aging and rejuvenation is a young research held, in its first 20 years a lot of knowledge has been produced. Nowadays, important scientific journals and conferences include SAR-related topics in their scope of interest. This fast growing and wide range of dissemination venues pose a challenge to researchers to keep tracking of the new findings and trends in this area. In this work, we collected and analyzed SAR research data to detect trends, patterns, and thematic gaps, in order to provide a comprehensive view of this research held over its hrst 20 years. Adopted the systematic mapping approach to answer research questions such as: How the main topics investigated in SAR have evolved over time? Which are the most investigated aging effects? Which rejuvenation techniques and strategies are more frequently used?CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorDissertação (Mestrado)Embora o envelhecimento e rejuvenescimento de software seja um campo de pesquisa novo, em seus primeiros 20 anos muito conhecimento foi produzido. Hoje em dia, revistas e conferências científicas importantes incluem temas relacionados a SAR no seu âmbito de interesse. Este crescimento rápido e a grande variedade de locais de disseminação representam um desafio para os pesquisadores para manter o acompanhamento das novas descobertas e tendências nesta área. Neste trabalho, foram coletados e analisados dados de pesquisa em SAR para detectar tendências, padrões e lacunas temáticas, a hm de proporcionar uma visão abrangente deste campo de pesquisa em seus primeiros 20 anos. Adotou-se a abordagem de mapeamento sistemático para responder a perguntas de pesquisa, tais como: Como os principais temas investigados em SAR têm evoluído ao longo do tempo? Quais são os efeitos do envelhecimento mais investigados? Quais técnicas e estratégias de rejuvenescimento são mais frequentemente usadas

Photovoltaic-powered wireless communication system for rural schools outside national utility grid

Access to global information is inarguably one of the key ways of bringing development to any community. In developing worlds, many rural schools lie outside both the Internet Service Provider’s (ISP) cable network and the national utility grid. Rapid developments in information and communication technology (ICT) continue to widen the digital divide between urban and rural schools. In South Africa, although these rural areas are outside the ISP’s cable network, they enjoy excellent mobile (cellular) communications network coverage. Fortunately, leading mobile operators in the country (MTN and Vodacom) have incorporated mobile data packet services into their cellular communication networks since 2002. A stand-alone photovoltaic (PV) system for powering ICT equipment in off grid rural schools was designed and installed; and its performance monitored. Performance of the system was considered in two categories, which are; cost and service performance. In cost performance, return on investment (ROI) and payback period (PB) are the two critical considerations. The PV system designed in this study gave an impressive ROI and PB of 286percent and 5 years, respectively. In order to monitor and evaluate the service performance a data acquisition system (DAS) was designed and installed. Besides proving the potential of PV in powering ICT equipment, results from the DAS also suggested a more efficient way of employing PV as a power source for powering equipment that is based on Switched-Mode Power Supply Units. Concurrent and continuous change in irradiance and temperature result in a four-segment pattern of rising and falling module efficiency throughout the day. Generally, modules produce more energy on cooler sunny days than hotter sunny days. Infrared (IR) Thermography was also used as part of both indoor and outdoor module tests. During indoor tests at pre-deployment stage, IR Thermography showed development of hot spots in mismatched cells of reverse-biased modules. On the outdoors, IR Thermography reiterated the effect of bird droppings on module surfaces by showing hot spots forming on areas covered by the droppings. For internet connectivity, a customized Mobile Internet Device (MIDevice) was designed, built and tested. The device allows remote computer systems to be connected to the Internet via the already existing mobile communication network k using General Packet Radio Services (GPRS). An entire rural school local area network (LAN) can be connected to the Internet via a single MIDevice. An experimental setup was designed in order to monitor and evaluate performance of GPRS in specific and mobile Internet solutions in general. Results obtained proved that GPRS can indeed be a solution for remote Internet connectivity in rural schools. In order to improve performance of GPRS or mobile Internet connections, caching, pop-up blocking and proxy filtering are necessary.Thesis (MSc) -- Faculty of Science and Agriculture, 200

Photovoltaic-powered wireless communication system for rural schools outside national utility grid

Access to global information is inarguably one of the key ways of bringing development to any community. In developing worlds, many rural schools lie outside both the Internet Service Provider’s (ISP) cable network and the national utility grid. Rapid developments in information and communication technology (ICT) continue to widen the digital divide between urban and rural schools. In South Africa, although these rural areas are outside the ISP’s cable network, they enjoy excellent mobile (cellular) communications network coverage. Fortunately, leading mobile operators in the country (MTN and Vodacom) have incorporated mobile data packet services into their cellular communication networks since 2002. A stand-alone photovoltaic (PV) system for powering ICT equipment in off grid rural schools was designed and installed; and its performance monitored. Performance of the system was considered in two categories, which are; cost and service performance. In cost performance, return on investment (ROI) and payback period (PB) are the two critical considerations. The PV system designed in this study gave an impressive ROI and PB of 286percent and 5 years, respectively. In order to monitor and evaluate the service performance a data acquisition system (DAS) was designed and installed. Besides proving the potential of PV in powering ICT equipment, results from the DAS also suggested a more efficient way of employing PV as a power source for powering equipment that is based on Switched-Mode Power Supply Units. Concurrent and continuous change in irradiance and temperature result in a four-segment pattern of rising and falling module efficiency throughout the day. Generally, modules produce more energy on cooler sunny days than hotter sunny days. Infrared (IR) Thermography was also used as part of both indoor and outdoor module tests. During indoor tests at pre-deployment stage, IR Thermography showed development of hot spots in mismatched cells of reverse-biased modules. On the outdoors, IR Thermography reiterated the effect of bird droppings on module surfaces by showing hot spots forming on areas covered by the droppings. For internet connectivity, a customized Mobile Internet Device (MIDevice) was designed, built and tested. The device allows remote computer systems to be connected to the Internet via the already existing mobile communication network k using General Packet Radio Services (GPRS). An entire rural school local area network (LAN) can be connected to the Internet via a single MIDevice. An experimental setup was designed in order to monitor and evaluate performance of GPRS in specific and mobile Internet solutions in general. Results obtained proved that GPRS can indeed be a solution for remote Internet connectivity in rural schools. In order to improve performance of GPRS or mobile Internet connections, caching, pop-up blocking and proxy filtering are necessary.Thesis (MSc) -- Faculty of Science and Agriculture, 200

Envelhecimento de software utilizando ensaios de vida acelerados quantitativos

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de ProduçãoEste trabalho apresenta uma abordagem sistematizada para acelerar o tempo de vida de sistemas que são acometidos pelos efeitos do envelhecimento de software. Estudos de confiabilidade voltados para estes sistemas necessitam realizar a observação dos tempos de falhas causadas pelo envelhecimento de software, o que exige experimentos de longa duração. Esta exigência cria diversas restrições, principalmente quando o tempo de experimentação implica em prazos e custos proibitivos para o estudo. Neste sentido, este trabalho apresenta uma proposta para acelerar a vida de sistemas que falham por envelhecimento de software, reduzindo o tempo de experimentação necessário para observar as suas falhas, o que reduz os prazos e custos das pesquisas nesta área. A fundamentação teórica deste estudo contou com um arcabouço conceitual envolvendo as áreas de dependabilidade computacional, engenharia de confiabilidade, projeto de experimentos, ensaios de vida acelerados e o estudo da fenomenologia do envelhecimento de software. A técnica de aceleração adotada foi a de ensaios de degradação acelerados, a qual tem sido largamente utilizada em diversas áreas da indústria, mas até o momento não tinha sido usada em estudos envolvendo produtos de software. A elaboração dos meios que permitiram aplicar esta técnica no âmbito da engenharia de software experimental, abordando especialmente o problema do envelhecimento de software, é a principal contribuição desta pesquisa. Em conjunto com a fundamentação teórica foi possível avaliar a aplicabilidade do método proposto a partir de um estudo de caso real, envolvendo a aceleração do envelhecimento de um software servidor web. Dentre os principais resultados obtidos no estudo experimental, destaca-se a identificação dos tratamentos que mais contribuíram para o envelhecimento do software servidor web. A partir destes tratamentos foi possível definir o padrão de carga de trabalho que mais influenciou no envelhecimento do servidor web analisado, sendo que o tipo e tamanho de páginas requisitadas foram os dois fatores mais significativos. Outro resultado importante diz respeito à verificação de que a variação na taxa de requisições do servidor web não influenciou o seu envelhecimento. Com relação à redução no período de experimentação, o método proposto apresentou o menor tempo em comparação aos valores previamente reportados na literatura para experimentos similares, tendo sido 3,18 vezes inferior ao menor tempo encontrado. Em termos de MTBF estimado, com e sem a aceleração do envelhecimento, obteve-se uma redução de aproximadamente 687 vezes no tempo de experimentação aplicando-se o método proposto. This research work presents a systematic approach to accelerate the lifetime of systems that fail due to the software aging effects. Reliability engineering studies applied to systems that require the observation of time to failures caused by software aging normally require a long observation period. This requirement introduces several practical constraints, mainly when the experiment duration demands prohibitive time and cost. The present work shows a proposal to accelerate the lifetime of systems that fail due to software aging, reducing the experimentation time to observe their failures, which means smaller time and costs for research works in this area. The theoretical fundamentals used by the proposed method were based on concepts of the following areas: computing dependability, reliability engineering, design of experiments, accelerated life tests and the software aging phenomenology. The lifetime acceleration technique adopted was the quantitative accelerated degradation test. This technique is largely used in several industry areas, however until the moment it hadn't been used in the software engineering field. The specification of means that allowed applying this technique to the experimental software engineering area, especially to approach the software aging problem, it is considered the main contribution of this research work. Also, it was possible to evaluate the applicability of the proposed method in a case study related to the software aging acceleration of a real web server. An important result was the identification of treatments that contributed to the web server aging. Based on these treatments was possible to define a workload standard that most influenced the aging effects on the web server analyzed, where the page size and page type were two significant factors. Another important result of this case study is regarding the request rate variability, that hadn't influence on the aging of the investigated web server software. Regarding the reduction of the experimentation period, the proposed method showed a shorter duration than values from similar experiments previously published, being 3.18 times less than the shorter experimentation time found in the literature. In terms of MTBF estimates, obtained with and without the aging acceleration, it was possible to achieve a reduction of approximately 687 times of the experimentation time using the proposed method

Triangle Journal News, volume 6, number 4

Co-Editors: Allen Cook, John Stilwell. Staff Writers: Vincent Astor. National News Editor: Mike Morgan. Contributors: Jim Norcross, Gary Salles. Production: Vincent Astor, Allen Cook, Bob Dumais, John Stilwell. Advertising: Vincent Astor, Bob Dumais. Special thanks to Rhodes College and the Paul Barret Jr. Library for providing initial scanning of this collection.https://digitalcommons.memphis.edu/speccoll-mss-outmemphis4/1063/thumbnail.jp

An investigation of the partnering strategies in application service provision: A vendor perspective

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This research aims to investigate the partnering strategies in Application Service Provision (ASP) from a vendor's perspective. Although some attention was recently given to the ASP model, the main focus of the published academic work was essentially on the customer's side. This research focuses on ASP vendors, and aims at studying the partnering strategies used by these in order to source the different ASP model components. From the studied literature, it was found that the ASP model relies on 4 main infrastructural layers for delivering services: the data storage layer, the server layer, the network layer, and the application layer. Due to the different nature of each of these layers in terms of the required technology, it was concluded that ASP is a complex service, for which the required resources and capabilities are unlikely to be owned by one single company, thus the importance of studying the partnering strategies needed for ASP vendors. Through the use of Transaction Cost Economics (TCE) and the Resource-based View (RBV), predictions were made about the expected sourcing modes (market, integration, or strategic alliance) for each of the ASP layers. The next phase was to study six ASP cases, in which the partnering strategies of each firm for each ASP layer were studied. The main result from this analysis was that the actual outcomes from the case studies did not fully match the predictions that were initially made. A cross-case analysis was then undertaken by reapplying TCE and RBV to the studied cases. In this phase, for each ASP layer in each case study TCE and RBV attributes were investigated, and the drawn conclusions were two fold. First, the initial assumption that the software layer is the core layer of the model, based on which the predictions were made, was rather flawed; it was found that although many ASP vendors draw value from the application layer, several others rely on other ASP layers. Secondly, it was concluded that the two used theories - TCE and R-BV - did not, independently, explain all the actual sourcing modes of the studied ASP vendors, though RBV showed more explanatory power than TCE. Furthermore, it was demonstrated that the combination of TCE and RBV, in the context of this study, offers more explanatory power than if the two theories were used independently. Although this is an important finding in the context of ASP, the implications on IS research is tremendous, where multiple-theory applications are increasingly called for

Aeronautical engineering: A cumulative index to a continuing bibliography (supplement 248)

This publication is a cumulative index to the abstracts contained in Supplements 236 through 247 of Aeronautical Engineering: A Continuing Bibliography. The bibliographic series is compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number and accession number

The 23rd Annual International Conference on Soils, Sediments and Water

Conference at a Glance Monday, October 15, 2007 (workshop #1-2: 9:00am – 5:00pm, workshop #3: 10am – 5:00pm, workshop #3, 10:00am – 5:00pm, workshops #4, 5, & 6, 1:00pm – 5:00pm, workshop #7 & 8, 2-5pm) 1) Compliant Analysis of Water, Wastes and Related Solid Environmental Samples Using Inductively Coupled Plasma Atomic Emission and Mass Spectrometry 2) In-Situ Chemical Oxidation Workshop 3) Theory and Use of Field Portable X-ray Fluorescence for Soil Analysis 4) The 2007 MCP Audit – A Case Study Approach 5) “Lies, Damned Lies, and Statistics”: Avoiding Pitfalls in Environmental Sampling 6) Evaluating Monitored Natural Attenuation of MTBE and TBA 7) Environmental Forensic Techniques for Classic and Emerging Contaminants 8) Environmental Fate of Hydrocarbons in Soils and Groundwater Tuesday, October 17, 2007 Morning 8:30am – 9:00am Conference Welcome and Overview 9:00am – Noon, Sessions are concurrent Session 1: Ethics in Environmental Practice: Responsibilities, Benefits & Case Examples Session 2a: Pesticides Session 2b: Vapor Intrusion Session 3a: Brownfields Session 3b: Fisherville Mill - Assessment and Cleanup of a Brownfields Site on the Blackstone River Session 4a: Environmental Fate Session 4b: Sediments Afternoon 1:30 to 5:30pm, Sessions are concurrent Session 1: Phytoremediation Session 2: Biotechnology Session 3: Tungsten Session 4: Combining Chemical and Biological Technologies for Soil and Groundwater Remediation Session 5: Environmental Forensics Poster Sessions 4:00 – 6:00pm Arsenic Environmental Fate Environmental Forensics Pesticides Phytoremediation Remediation Sediments Tungsten Vapor Instrusion Social 4:30 – 6:00pm, exhibit area, 1st floor Workshops (Evening, 7:00 – 10:00pm) 9) In-Situ Thermal Remediation 10) Applied Chemical Fingerprinting in Environmental Forensics 11) Utilization of Stable Isotopes in Environmental and Forensic Geochemistry Studies 12) Professional Ethics, Professional Conduct, and Environmental Professionals Wednesday, October 17, 2007 Morning 8:30am – Noon, Sessions are concurrent Session 1: Gasoline Oxygenates I Session 2: Remediation I Session 3: Regulatory Session 4: Coated and Uncoated Microbubble Ozone Remediation Projects Afternoon 1:30 – 5:30pm, Sessions are concurrent Session 1: Gasoline Oxygenates II Session 2: Perchlorate/MECs Session 3: Analysis Session 4: Chemical Oxidation Poster Sessions 4:00 – 6:00pm Acid Mine Drainage Analysis Bioremediation Brownfields Chemical Oxidation Emerging Issues with Energy in the Environment Heavy Metals MECs Miscellaneous MTBE Radionuclides Site Assessment Social 4:30 – 6:00pm, exhibit area, 1st floor Workshops (Evening, 7:00 – 10:00pm) 13) Critical Exposure Pathways 14) Characterizing PAH Bioavailability in Sediments for Remedial Decision-Making 15) Theory and Application of Molecular Biological Tools (“MBTs”) and Biogeochemistry to Bioremediation Process Monitoring and Monitored Natural Attenuation Programs 16) Geochemical Evaluations of Metals in Environmental Media: How to Distinguish Naturally Elevated Metals Concentrations from Site-Related Contamination Thursday, October 18, 2007 Morning 8:30am – Noon Sessions are concurrent Session 1: Bioremediation Session 2: Remediation II Session 3: Modeling Session 4: Risk Assessment Afternoon 1:30pm – 5:00pm Sessions are concurrent Session 1: Heavy Metals Session 2: Innovative Technologies Session 3: Site Assessmen

Bronx Community College of the City University of New York Catalog 1994-96

Course catalog for Bronx Community College for 1994-96

Bronx Community College of the City University of New York Course Catalog 1986-88

Course catalog for Bronx Community College for 1986-88